Being Kind to Your Future Self: Probability Discounting of Health Decision-Making.

INTRODUCTION: Nearly 50 % of patients with chronic medical illness exhibit poor treatment adherence. When making treatment decisions, these patients must balance the probability of current side effects against the probability of long-term benefits. This study examines if the behavioral economic construct of probability discounting can be used to explain treatment decisions in chronic disease. METHODS: Thirty-eight nonadherent and 39 adherent patients with multiple sclerosis (MS) completed a series of hypothetical treatment scenarios with varied risk and benefit probabilities. RESULTS: As described by a hyperbolic probability discounting model, all patients reported decreased medication initiation as the probability of treatment efficacy decreased and the probability of treatment side effects increased. When compared to adherent patients, nonadherent patients significantly devalued treatment efficacy and inflated treatment risk. DISCUSSION: The methods in this study can be used to identify optimal risk/benefit ratios for treatment development and inform the process by which patients make treatment decisions.